1. Field of the Invention
This invention relates generally to optical and electronic bonding equipment and more particularly, to apparatus and methods for precisely locating the position of a lasing gap of a laser chip and correlating it with a feature on the chip.
2. Description of the Related Art
Precise alignment of surfaces in the placement of optoelectric components has received much attention. This is particularly true in VLSI circuit elements where the patterning of the circuit is microscopic or nearly microscopic. Many small components are typically bonded to these circuits. The problem with placing these small components with high precision i.e. within microns, is accurately locating and correlating the component and placement position. Also, the component must be moved to the exact placement position without error.
In a typical lightwave application, the output of a semiconductor laser chip is coupled to an optical transmission line such as an optical fiber or waveguide. Often a ball lens is used to optimize coupling between the laser and the fiber. If low coupling efficiencies are acceptable, current precision assembly equipment and conventional alignment techniques can be used. See, for example, U.S. Pat. No. 4,899,921 to Bendat et al. If, however, highly precise alignment is required for greatest coupling efficiency, then current practice dictates that active alignment be used. This is performed by fixturing one element, e.g. the laser/ball lens assembly, energizing the laser, and moving the fiber around until the greatest output is realized. This is an imprecise and time consuming process that limits the range of automated solutions because of its complexity. Accordingly, a need exists for a method and apparatus which can achieve a highly precise alignment in a manner that is less time consuming and is conducive to large scale automation.